Electrical insulating section for metallic conduits



Sept. 26, 1944. 5 K. NEWTON ELECTRICAL INSULATING SECTION FO R METALLIC CONDUITS Filed May 25, 1942 INVENTOR. W /(M ATTO EY.

Patented Sept. 26, 1944 EIECTBIOAL INSULATING BECI ION FOR METALLIC OONDUITS Evans K. Newton.

to Hooker Electroch Falls. N. 1.. a corporal! Niagara Falls, N. Y., assignor crnioal Company,

on of New York Niagara Application]!! 25, 1942, Serial No. 444,493

My invention relates more particularly to insulating sections for metallic conduits connected to active metallic electrode compartments of electrolytic cells. such as alkali halogen cells, and carrying away therefrom hot gases. such as hydrogen, saturated with moisture and carrying traces of conductive substance, such as caustic alkali.

In the operation of electrolytic alkali halogen cells it is customary to connect them in electrical series and the number of cells in the series may be such that a diflerence of potential oi 300 volts the gen and aqueous caustic alkali are produced simultaneously. The hydrogen bubbles vigorously through the solution caustic alkali, which may be at 90" C., and issues at that temperature saturated with moisture carrying traces oi caustic alkali. It is customary to carry the hydrogen away to an iron header pipe through iron connecting pipes iormed with vertical legs to permit refluxing and provided with sections of non-conducting material, such as rubber or glass. This method of collecting the hydrogen has heretoiore been satisfactory: but there has now arisen a tendency to extend such circuits so that the potential between the ends of the circuit may be as much as 750 volts. The inner surface of the insulating glass tubes are wet with alkaline condensate and under these conditions flash-over through the glass tube is liable to occur. The object of my invention is to prevent this by improving the insulating properties of the tubular glass insulating sections. 1 accomplish this object in simple manner that will be better understood by reierence to the drawing, in which;

Fig. i is a sectional elevation of the simplest" form of my invention, and

Fig. 2 is a sectional elevation oi a modified form of my invention.

Referring to Fig. 1. l is a portion of the me.- tallic conduit leading irom the cell (not shown) 2 is a section of conduit or tube, which may be 0! non-conducting material, connected to conduit l as by rubber sleeve tinuation oi conduit l. l is a portion oi. the metallic conduit connected to the main header (not shown). 5 is a section of conduit or tube similar to tube 2. which. may also be 0! non-conductiormihg a continuation oi conduit 4 and connected'thereto as by rubber sleeve 8. conduit sections 2 and. i preferably extend vercally and in coaxiai alignment, with their I and forming a conends separated by insulating gap 1. Portions of tubes 2 and b on each side of gap 1 are enclosed by Jacket I. This is also preierably'oi nonconductlng material and co-axial with conduits between Jacket I, on 2 and i. on the other. is therefore of circular annular cross section and readily closed at its ends, as by rubber stoppers l. Jacket 8 therefore forms with stoppers I and tubes 1 and 5 a gas and liquid tight-chambe: or enclosure l0 extending around can I. In the construction described, the gas passes directly from tube I to tube 5. The gas in the annular space between tube 5 and jacket I is therefore/quiescent, and by placing these tubes in a perpendicular position, with tube I above tube 2, as in the drawing, the condensate may be caused to drip from tube 5 directly into tube 2. The condensate is therefore prevented irom wetting the surfaces of chamber ill and thereby iorming a conductive path irom the tip of tube i to the end 0! tube 2. In almost any inclined position, with tube I uppermost, the same result is secured to a greater or less extent, but the vertical is obviously the position in which, for a given length, chamber III is most ellective. However, in cases where this position is impracbeen found to be very the flash-overs reierred to.

Various modifications oi the construction illustrated will suggest themselves to any person skilled in the art. For instance. ii Jacket Q is of non-conducting material, tubes 2 and 5 may be oi metal, and vice versa, provided chamber ill is long enough to remain substantially dry inside. It is however essential that either jacket I or tube t be non-conducting.

Ii preferred, upper tube 5 may be the inlet tube and lower tube 2 the exit, but in that case the header (not shown) into which tube 2 would drain would have to be located below the insulating section and provided with a means for separating and be provided as illustrated in when the header is supported overhead and conduit 4 is supported therefrom and conduit 1 supported by and close to the cell, no mechanical strength is needed beyond that provided by the construction oi Fig. 1.

I claim as my invention:

1. In a system of electrolytic cells for production of chlorine and caustic alkali from an aqueous electrolyte, provided with means for passing electric current therethrough and from cell to cell between electrodes of alternate polarity and for collecting in a common conductive header through a conduit leading to said header from each individual cell hydrogen evolved upon the cathode thereof and laden with moisture forming in said conduits condensate rendered conducting by caustic alkali in solution therein, an electrically insulating section for said conduit comprising a chamber having non-conducting walls forming a gas and liquid-tight closure with adjoinin portions oi said conduit, one portion of said conduit communicating with said chamber at the lower part thereof, the other portion of said conduit entering said chamber at the upper part thereof, projecting downward therein for a substantial distance and terminating in an open end a substantial distance above the bottom oi said chamber with a clear gap between, the nonconductin: walls of the upperpart of said chamber surrounding the entering portion or said conduit being substantially spaced therefrom to form aaoasso therewith a quiescent space the walls of which remain unwetted by condensate.

2. In a system of electrolytic cells for production of chlorine and caustic alkali from an aqueous electrolyte, provided with means for passing electrip current therethroush and from cell to cell between electrodes of alternate polarity and for collecting in a common conductive header through a conduit leading to said header from each individual cell hydrogen evolved upon the cathode thereof and laden with moisture forming in said conduits condensate rendered conducting by caustic alkali in solution therein, an electrically insulating section for said conduit comprising a chamber having non-conducting walls forming a gas and liquid-tight closure with adjoining portions of said conduit, one portion or said conduit communicating with said chamber at the lower part thereof, the other portion oi said conduit entering said chamber at the upper part thereoi, proiecting vertically downward therein for a substantial distance and terminating in an open end square with its axis a substantial distance above the bottom of said chamber with a clear gap between, the non-conducting walls of the upper part of said chamber surrounding the entering portion of said conduit being substantially space therefrom to form therewith a quiescent space the walls of which remain unwetted by con- EVANB K. NEWTON. 

